This invention relates to mixtures of fluorinated hydrocarbons and more particularly to constant boiling fluorocarbon mixtures which comprise 1,1,2,2-tetrafluoroethane and 1,1,1,2-tetrafluorochloroethane. Such mixtures are useful as refrigerants, heat transfer media, gaseous dielectrics, expansion agents, aerosol propellants, working fluids in a power cycle and solvents, and are potentially environmentally safe substitutes for trichlorofluoromethane and dichlorodifluoromethane which are industry standards for refrigerant and aerosol propellant applications.
Recently the long term environmental effects of trichlorofluoromethane and dichlorofluoromethane have come under substantial scientific scrutiny. It has been postulated that these materials break down in the stratosphere under the influence of ultraviolet light to release chlorine atoms which are theorized to undergo chemical reactions in the stratosphere which may lead to depletion of the stratospheric ozone layer which shields the earth from harmful ultraviolet radiation. A substantial reduction in this ozone layer could have a serious impact on the quality of life on earth.
There is a continuing need in this art for new materials having new combinations of properties for use in the various applications mentioned above. In view of the potential environmental problem discussed above, there is a particular need for new materials possessing properties which make them useful in the subject applications, which materials are potentially environmentally safe.
There is a limit to the number of single fluorinated hydrocarbon substances which would be candidates for such environmentally safe materials. Mixtures of known materials, however, might be used if the desired combination of properties can be found in a given mixture. Simple mixtures, however, create problems in design and operation of refrigeration and other equipment because of segregation of the components in the liquid and vapor phases. To avoid such segregation problems it is particularly desirable to discover new azeotropic or constant boiling blends of fluorocarbons. Such blends would not suffer from such segregation problems. Unfortunately, however, azeotropism is an unpredictable phenomenon thus complicating the search for novel azeotropic compositions which possess desirable combinations of properties.
An object of the present invention is to provide a new azeotropic or constant boiling composition of matter comprising fluorocarbon components.
Another object of the invention is to provide new, low boiling azeotropic or constant boiling mixtures which have properties which make them particularly useful as refrigerants and aerosols.
Still another object of the invention is to provide new, low boiling, azeotropic or constant boiling mixtures, useful in producing refrigeration or as aerosol propellants which are potentially environmentally safe.
Other objects of the invention will become apparent from the following description.